TW201410977A - Method and pump arrangement for evacuating a chamber - Google Patents

Abstract

The invention relates to a method for evacuating a chamber, wherein a pump arrangement composed of a booster pump and of a downstream forepump is connected to the chamber. In the method, the booster pump is accelerated, gas from the chamber is introduced into the booster pump, such that from the booster pump there is temporarily extracted an excess power which exceeds the power provided by the drive of the booster pump. The gas is delivered to the outlet of the booster pump. The gas is discharged through a bypass valve for as long as the outlet pressure of the booster pump lies above a predefined threshold value, and the gas is conducted onward to the forepump when the outlet pressure of the booster pump has fallen below the threshold value. The gas supplied by the booster pump is compressed by means of the forepump. The invention also relates to a pump arrangement for carrying out the method. By means of the invention, it is possible for the forepump to be designed for a smaller mass flow than the booster pump.

Description

Method for draining a cavity and pump configuration

The present invention relates to a method and a pump configuration for evacuating a chamber. The pump configuration coupled to the chamber includes a booster pump and a downstream front pump.

In many technical applications, there is currently a need for a chamber that can be evacuated to a predetermined vacuum in a short period of time. One of them is a lock chamber, and most products are introduced into a vacuum chamber through the lock chamber. Such products may be, for example, mass produced articles such as solar cells, displays, etc., implemented in the vacuum chamber in a number of separate manufacturing steps. These products need to be introduced into the vacuum chamber in a shorter cycle time. It is not unusual for a lock chamber having a volume of one hundred liters to be evacuated to a pressure of less than 10 ^-2 mbar for much less than 10 seconds.

To evacuate the latching chambers, a pump configuration consisting of two series connected pumps is generally used, wherein the first pump configuration is commonly referred to as a boost pump, and the downstream pump configuration is often referred to as a front pump Set up the pump. The series connection of the two pump configurations is advantageous because, according to the ideal gas law (pressure * volume = constant; assuming constant temperature), the front pump can be designed for a much smaller volume than the booster pump flow.

However, if a lock chamber is to be evacuated from atmospheric pressure for a very short period of time, the booster pump initially delivers a high volume flow at high pressure, with the result that a large volume of flow reaches the outlet of the booster pump. The pump can be handled before the bulk flow is cumbersome and expensive.

It is an object of the present invention to provide a pump configuration that allows a chamber to be quickly evacuated at a lower cost to the device. Taking the above-mentioned conventional technology as a starting point, the purpose of the alliance is achieved by the characteristics of the scope of the independent patent application. The scope of the dependent patent application is related to advantageous embodiments.

In the method according to the invention, the booster pump is initially accelerated. The gas from the chamber to be vented is then directed to the booster pump such that the booster pump temporarily draws excess power beyond the power provided by the booster pump. As long as the outlet pressure in the booster pump is above a predetermined threshold, the gas delivered to the outlet of the booster pump passes through a bypass valve. The gas is forwarded to the pre-pump when the outlet pressure of the booster pump has dropped below the threshold. The pre-load is used to compress the gas supplied by the booster pump.

Several wordings will be explained first. The terms "booster pump" and "front pump" indicate the order of the pumps in the pump configuration. These words do not impose a restriction on the configuration of the pump.

The present invention has confirmed that due to the acceleration of the booster pump and subsequent extraction of excess power, the gas from the chamber can be delivered to the booster pump at a high pressure that allows the gas to bypass the direct discharge of the pre-pump. Only when the emptying procedure has been carried out to the booster pump can no longer compress the gas to the corresponding The pre-load is additionally used for further compression when the pressure is reached. With the present invention, the pre-pump can be configured to be used not only for a smaller volume flow than the booster pump but also for a mass flow that is smaller than the booster pump.

Typically, the outlet at the bypass valve is primarily atmospheric. In this case, the threshold corresponds to the atmospheric outflow. Therefore, as long as the outlet pressure of the booster pump is higher than atmospheric pressure, the gas is discharged through the bypass valve. At its peak, the outlet pressure of the booster pump may exceed atmospheric pressure by at least one bar, preferably at least 2 bar, and more preferably at least 3 bar. The gas compressed by the pre-pump can be similarly discharged to the environment at atmospheric pressure.

At the beginning of the evacuation procedure, typically atmospheric pressure is present in the chamber such that the evacuation procedure begins at atmospheric pressure. The inlet of the booster pump can be closed prior to initiating the evacuation procedure so that no gas from the chamber can enter the booster pump. The emptying procedure then begins when the gas is introduced into the booster pump.

In order to be able to deliver a large volume of flow at a high pressure (e.g., atmospheric pressure) at the beginning of the evacuation procedure, the booster pump must provide a high compression power. The high compression power is provided by the fact that during the emptying procedure, the boosting pump temporarily draws more compression power than is provided by the booster pump. The excess power exceeding the driving power is extracted by the kinetic energy of the booster pump. Therefore, the booster pump is braked and the speed of the pump is reduced.

Within the scope of the invention, the power extracted in the booster pump can be much higher than the drive power. For example, at its peak, the excess power may be greater than 50%, preferably greater than 100%, and more preferably greater than 200% of the driving power. In the case of a 100% excess power, the compression power is the drive Double the power.

Moreover, it is also possible to set the excess power not only instantaneously but also for a certain period of time. If the emptying procedure begins when the pressure of the chamber drops below the outlet pressure and ends when the final pressure in the chamber is reached, the period of time during which excess power is drawn may be extended, for example, beyond the emptying procedure. 10%, preferably more than 20%, and more preferably more than 50%. Due to the extraction of the excess power, the speed of the booster pump can be reduced by at least 5%, preferably by at least 10%, and more preferably by at least 25%.

In order to extract excess power from the pump to this extent, the pump must be able to obtain a corresponding amount of kinetic energy before the venting procedure begins. Therefore the pump is accelerated before the emptying process begins.

In order to provide suitable kinetic energy, the speed of the booster pump at the beginning of the evacuation procedure is preferably above 8000 rpm, preferably above 10,000 rpm, and more preferably above 12,000 rpm. The diameter of the rotating components is preferably greater than 5 cm, preferably greater than 10 cm, and more preferably greater than 20 cm.

If the gas from the chamber is introduced into the booster pump at substantially atmospheric pressure, the booster pump is subjected to a sudden load. Some types of pumps that are currently used as booster pumps, such as supercharged pumps, are generally less suitable for regulating such sudden loads. In an advantageous embodiment, a screw-type pump is used as a booster pump, and its preferred configuration is described in more detail below.

With the method of the present invention, a chamber having a volume greater than 100 L can be evacuated from atmospheric pressure to a pressure of less than 10 ^-2 mbar in less than five seconds. This may be of particular interest in the case where one of the orders of magnitude has to lock the chamber in a short cycle time to vent the occlusion application. The inlet to the lock chamber is primarily atmospheric, which means that when the inlet is opened to introduce a component into the lock chamber, atmospheric pressure is also assumed in the lock chamber. The outlet of the lock chamber is engaged with a vacuum chamber having a pressure of, for example, 10 ^-2 mbar. The lock chamber must therefore be vented to this pressure before the outlet can be opened to feed the component into the vacuum chamber.

If the cycle time of the lockout is, for example, 10 seconds, the time for extracting excess power from the booster pump may be, for example, 1 second, and the remaining cycle time is used to accelerate the booster pump to the start speed. More generally, the extraction time of excess power is preferably at least 5%, more preferably at least 10% of the cycle time. At least 30%, preferably at least 50%, and more preferably at least 70% of the cycle time, the power drawn by the booster pump is lower than the drive power, such that the booster pump is accelerated.

The invention also relates to a pump configuration. The pump configuration includes a booster pump and a front pump, wherein the booster pump outlet is connected to the inlet of the front pump. Between the booster pump and the front pump, a bypass valve is disposed, and the gas delivered by the booster pump can be discharged by the bypass valve while bypassing the front pump. The pump configuration also includes a control unit that is configured to output a control signal if the speed of the booster pump is above a predetermined speed threshold. The speed threshold is such that after exceeding the respective speeds, the booster pump is ready to extract excess power. The pumping configuration is adapted to evacuate a chamber in a short period of time in accordance with the method of the present invention.

The control signal can be transmitted to one of the chambers to be emptied In order to display the booster pump ready to proceed to the next emptying procedure. Thus the controller of the chamber can open the inlet of the booster pump whereby the booster pump is connected to the chamber. Gas from the chamber then enters the booster pump and the chamber is quickly emptied. When the gas enters the booster pump, the load suddenly increases, causing the speed of the booster pump to decrease.

The booster pump control unit can be further configured to accelerate the booster pump prior to the start of the emptying procedure such that the speed threshold is exceeded. In order to provide an appropriate amount of kinetic energy for extracting the excess power, the speed threshold is preferably higher than the boosting speed of the booster pump. The transmission rotational speed represents a rotational speed assumed to be a steady state when the suction pressure is 100 mbar. At the transmission speed, the driving power corresponds to the pump power, which means that the rotation speed of the booster pump remains unchanged. The speed threshold may be 10% higher, preferably 30%, and more preferably 50% higher than the transmission speed. In absolute values, the speed threshold may be, for example, at least 8000 rpm, preferably at least 10,000 rpm, and more preferably at least 12,000 rpm. Typically, pressurized boosters for use in one of the applications within the scope of the present invention operate at relatively low speeds. The speed of the 6,000 rpm is typically not exceeded when operating the booster pumps. In the case of the method according to the invention, the booster pump can also be accelerated beyond the transfer speed.

The configuration according to the invention may further comprise the chamber to be evacuated. To achieve this, the control unit of the configuration can be arranged to open the inlet of the pump after the speed threshold has been exceeded, and the booster pump connects the chamber through the inlet. Furthermore, the control unit can be configured to keep the inlet closed when the booster pump is accelerated.

In an advantageous embodiment, a screw-type pump is used as a The booster pump, wherein the two threaded screws are engaged with each other such that the gas is transferred from the suction side to the pressurized side between the coils. In order to withstand the high rotational speeds, the screws preferably have two threads in all cases such that the increased forces in the longitudinal direction of the screws cancel each other out. The threads of the screws are preferably in a double-thread configuration. Here, in a radial direction, there may be point symmetry of the screws such that the screws become their own image by rotating 180° about the longitudinal axis. The diameter of the screws is preferably greater than 10 cm, preferably greater than 15 cm, and more preferably greater than 20 cm, such that the screws as a whole have about the above dimensions.

In order for the screw-type pump to accommodate the bulk flow required in the case of a booster pump, the inlet orifice is preferably greater than 60%, preferably greater than 80%, and more preferably greater than the cross-sectional area of a screw. 100%. In order to keep the leakage loss low, it is arranged close to the pressing side, the radial distance between the casing of the pump and the thread of the screw is as small as possible (radial minimum spacing), for example less than 0.2 mm Preferably, it is less than 0.1 mm.

In the inlet region, in particular in the portion of the housing formed by the inlet opening, a suction gap may exist between the thread of the screw and the housing for allowing a large volume of flow to enter the working chamber of the pump in. The radial diameter of the suction gap is preferably 50 times, preferably 100 times, and more preferably 200 times larger than the radial minimum spacing. The suction gap may extend, for example, at least 15°, preferably at least 30° of the circumference of the housing. In the longitudinal direction, the suction may extend at least 20%, preferably at least 30%, and more preferably at least 40% of the length of one of the threads of the screw. The length of the suction gap preferably corresponds to a length of the 360° circle of the thread in the region. Therefore the thread has in the inlet region There is a large pitch. The first 360° turn may extend, for example, at least 20%, preferably 30%, and more preferably 40% of the length of the thread. In summary, the respective turns of the double-threaded thread preferably comprise at least three, and more preferably at least four complete 360° turns.

14‧‧‧ screw

15‧‧‧Pump housing

16‧‧‧Control unit; control and drive unit

17‧‧‧Drive motor

18‧‧‧ Gears

19‧‧‧ thread

20‧‧‧ suction side

21‧‧‧ Pressurized side

22‧‧‧First coil

23‧‧‧Second coil

24‧‧‧ entrance hole

25‧‧ ‧ suction gap

26‧‧‧First housing part

27‧‧‧Second housing part

28‧‧‧Transition edge

29‧‧‧ hole; line

35‧‧‧faced

40‧‧‧vacuum chamber

41‧‧‧Products

42‧‧‧Locking chamber

43,44‧‧Sliding door

45‧‧‧ conveyor belt

46‧‧‧Supercharged pump

47‧‧‧Front pump

48‧‧‧Valves

49‧‧‧ Bypass valve

50‧‧‧ Controller

The invention will now be illustrated by way of an advantageous embodiment with reference to the accompanying drawings in which: Figure 1: shows a pump configuration in accordance with the invention in connection with a latching chamber; Figure 2: shows a screw suitable for use in a configuration according to the invention Stereoscopic, partial cut-out diagram of the type of pump; Figure 3: shows a detailed structure of the pump from Figure 1 in an enlarged view; Figure 4: shows another state of the pump from Figure 3; Figure 5 : shows a schematic cross-sectional view of a screw-type pump suitable for one of the configurations of the present invention along one of the axes of a screw; and FIG. 6A/B: shows a section along the lines AA and BB of FIG.

In one of the vacuum chambers 40 shown in Figure 1, certain method steps are performed on a product 41. The product 41 shown in simplified block may be, for example, a majority of semiconductor components such as, for example, solar cells or displays. The method step can be a coating procedure. For this method step, the pressure in the vacuum chamber 40 must be below 0.5 mbar. In order to maintain the vacuum chamber at this pressure, a vacuum pump (not shown in Figure 1) is coupled to the vacuum chamber 40.

The vacuum chamber 40 is engaged with a latching chamber 42 by a latching member and the product 41 is introduced into the vacuum chamber through the latching chamber 42. The The latching chamber 42 has an inlet aperture and an outlet aperture, and the inlet aperture and the outlet aperture have sliding doors 43, 44. The sliding doors 43, 44 are controlled by a controller 50 such that they do not open simultaneously at any time. When the sliding door 43 is opened, it is mainly atmospheric pressure in the locking chamber 42. The latch has a volume such as 2001.

When the sliding door 43 is opened, the product 41 can be introduced into the locking chamber 42 by the conveyor belt 45. After the sliding door 43 has been closed again, the locking chamber 42 is evacuated by a pump arrangement connected to the locking chamber 42 such that the pressure in the locking chamber 42 corresponds to the vacuum chamber. A pressure of less than 0.5 mbar in chamber 40. After the emptying procedure is completed, the sliding door 44 is opened and the product 41 is introduced by the conveyor belts 45. The sliding door 44 is then closed to bring the locking chamber 42 to atmospheric pressure and the sliding door 43 is opened. So complete one of the loops in the lock. The cycle time for this cycle is approximately 10 seconds.

With regard to the emptying procedure itself, whereby the pressure in the lock chamber is reduced from atmospheric pressure to a final pressure of less than 0.5 mbar, a much shorter time than the cycle time can be obtained. This emptying procedure can be extended by, for example, five seconds.

In order to be able to evacuate one of the volumes during this short period of time, it is necessary to have a powerful pumping arrangement with a high suction capacity over the entire pressure range between atmospheric pressure and final pressure. This is provided by a pump configuration in accordance with the present invention, wherein, as shown in FIG. 1, a screw type pump as a booster pump 46 and a liquid ring vacuum pump as a front pump 47 are connected in series. . The liquid ring vacuum pump has a conventional configuration, so no detailed Detailed description.

To begin the emptying procedure, the booster pump 46 is initially accelerated to a speed that is much higher than the transfer speed. A valve 48 disposed between the booster pump 46 and the lock chamber 42 is closed such that no inlet from the lock chamber 42 is accessible to the booster pump 46. Therefore, the booster pump 46 has no load so that a relatively low driving power is sufficient to accelerate the booster pump 46.

When the booster pump 46 has been accelerated to a level exceeding a predetermined speed threshold, the control unit 16 of the booster pump 46 transmits a control signal to the controller 50 of the lock chamber. The controller 50 therefore has information that the booster pump 46 is ready for the next emptying procedure. When the lock chamber 42 is also ready for the next emptying procedure, the controller 50 can open the valve 48 such that the booster pump 46 can draw in air from the lock chamber 42. The air is delivered by the booster pump 46 and is compressed in the process such that the outlet of the booster pump 46 is primarily a pressure that is much higher than atmospheric pressure. At its peak, the outlet of the booster pump 46 can be primarily a pressure of 3 bar above atmospheric pressure.

A bypass valve 49 is disposed between the pre-pump 47 and the booster pump 46, and the outlet of the bypass valve 49 is primarily atmospheric. The bypass valve 49 is assembled as an overpressure valve such that as long as the pressure at the outlet of the booster pump 46 is higher than atmospheric pressure, compressed gas from the outlet of the booster pump 46 passes through the bypass valve 49. Automatically escape. If the pressure at the outlet of the booster pump 46 drops below atmospheric pressure, the bypass valve 49 closes. The gas is then received by the pre-pump 47 and further compressed such that the gas can be vented to the environment at atmospheric pressure.

The closer the pressure in the lock chamber 42 is to the final pressure, the lower the pressure between the booster pump 46 and the pre-pump 47 becomes. The front pump 47 train is configured such that it compresses the gas from the pressure to atmospheric pressure.

In this emptying procedure, the booster pump 46 receives a particularly high load. When the valve 48 is opened, the flow of air entering the booster pump 46 creates a sudden load. In addition, the booster pump 46 requires a high compression power since a large volume of flow enters at atmospheric pressure. The compression power exceeds the driving power of the booster pump 46, which means that an excess power is extracted by the booster pump 46. This excess power is obtained by the rotational rotation of the booster pump 46, which means that the rotational speed of the booster pump 46 is reduced in this state.

In order to provide the proper dynamic rotational energy, the booster pump 46 is accelerated to a high rotational speed above 10,000 rpm before the emptying procedure begins. Since the excess power is extracted, the rotational speed is reduced to 9000 rpm in one second. This remaining cycle time is used to accelerate the booster pump 46 to the initial speed. In this state, the driving power is therefore higher than the compression power extracted by the booster pump 46.

The booster pump 46 that first withstands these loads and then has the desired pumping capacity over the entire pressure range is illustrated below.

A screw-type pump suitable as a booster pump includes, as shown in FIG. 2, two screws 14 housed in a pump housing 15. Since the pump housing 15 is not fully shown, one of the screws 14 can see the entire length while the other screw 14 is largely obscured by the pump housing 15. Such The two screws 14 are engaged with each other, which means that the threaded projection of one screw 14 engages in the recess between the two threaded projections of the other screw 14.

The pump comprises a control and drive unit 16, wherein for each screw 14, an electronically controlled drive motor 17 is provided. The electronic controllers of the drive motors 17 are arranged such that the two screws 14 operate in full synchronism with each other and the threaded projections of the screws 14 are not in contact. In order to additionally protect the screws 14 from damage, the two screws 14 have in one case a gear 18. If the electronic synchronization of the screws 14 fails, the gears 18 intermesh and create a positive coupling of the two screws 14.

Each screw 14 has two threads 19 such that the pump has a total of four threads 19. These threads 19 extend in each case from a suction side 20 at the center of the screw 14 to a pressurized side 21 at the outer end of the screw 14. The two threaded threads of a screw 14 are oriented in opposite directions such that they operate from the suction side 20 to the side of the pressurized side 21.

Each thread 19 includes a first coil 22 and a second coil 23. The threads 19 thus have a double-threaded thread, which means that the coils 22, 23 are interdigitated such that they together form a double helix. The two coils 22, 23 are formed such that the threads 19 are symmetrical in the radial direction. When the screw 14 is viewed from the pressing side of the first thread 19 to the pressing side of the second thread 19, the screw 14 is more symmetrical in a longitudinal direction.

The threads 19 are assembled such that in the region of the suction side 20 a smaller volume is enclosed between two adjacent threaded projections than in the region of the pressurized side 21. Therefore, the volume of the working chambers corresponding to the volume enclosed between the threaded projections is reduced from the suction side to the pressurized side, such that The gas contained in the working chamber is compressed in a path from the suction side to the pressurized side.

The pump housing 15 has an inlet aperture 24 and is configured to provide access to the suction side 20 of all four threads 19. To allow a large volume of flow into the pump, the inlet aperture 24 has a large cross section. In the exemplary embodiment, the inlet aperture 24 has a larger cross-sectional area than the circular contour occupied by a screw 14.

In order to further increase the volume flow into the working chambers, a suction gap 25 is formed in the housing 15 of the pump, and the suction gap 25 connects the inlet opening 24 and continues the screw 14 in the circumferential direction. profile. In the longitudinal direction, the suction gap 25 extends about half of the length of the thread 19 between the suction side 20 and the pressure side 21. In the circumferential direction, the size of the suction gap 25 varies with the inlet opening; the more the inlet opening 24 extends to the side of each point, the shorter the length of the suction gap 25 in the circumferential direction of the point. At the widest point of the inlet aperture 24, the suction gap 25 extends a circumferential angle of approximately 45°. In the region where the inlet aperture 24 no longer covers the suction gap 25, the inlet aperture 24 extends a circumferential angle of approximately 120[deg.]. The size of the suction gap 25 in the radial direction corresponds to the distance between the pump housing 15 and the contour of the screw 14 in this region. The spacing is in the range of approximately 10 mm.

Due to the suction gap, the gas is no longer restricted to enter the working chambers radially, but the gas can also move through a threaded projection and through the suction gap into the working chamber. In this way, the volume flow into the working chamber is further increased.

Another contribution to increasing the volume flow into the working chamber is This is achieved by the fact that there is a distance between the suction side 20 of the first thread 19 of the screw 14 and the suction side 20 of the second thread 19 of the screw 14. In this manner, at the center of the screw 14, leaving the gas can also enter the space of the working chamber radially.

The region in which the suction gap 25 extends (= the first housing portion 26) can be used to fill the working chambers. In the second housing portion 27 of the connection, the distance between the housing and the contour of the screw 14 is technically as small as possible (radial minimum spacing). This compression occurs in the second housing portion and leakage from a working chamber into the next working chamber is not necessary.

A transition edge 28 is formed in the transition from the first housing portion 26 to the second housing portion 27. The transition edge 28 extends the entire section 25 in a circumferential direction and defines a transition from the suction gap 25 to the second housing portion 27, wherein the radial minimum spacing exists between the housing 15 and the screw 14. .

When the working chamber has passed into the second housing portion, in other words, when the threaded projection defining the working chamber to the suction side has formed a latch with the transition edge 28, compression begins. The transition edge 28 is configured such that a latching relationship between the threaded projection and the transition edge 28 occurs when the working chamber still has its maximum volume.

When viewed from the circumferential direction, the transition edge 28 is closed at an angle to the transverse direction that is less than a gradient of the threaded projection that forms a latch with the transition edge 28. What is achieved in this way is that one of the locking between the threaded projection and the transition edge 28 does not occur suddenly but is extended for a short period of time. In this way, the operational noise of the pump is reduced.

The true volumetric compression system occurs shortly after the locking of the working chamber. The other threaded rings used to seal the abutments also produce a thermal compression.

At the pressurized side 21 of the thread 19, the gas is discharged from the working chamber. The compressed gas from the pressurized sides 21 located on the outside is sent together to a central outlet opening through a hole 29 in the pump housing 15. The exit aperture (not visible in the figures) is configured to oppose the inlet aperture 24. As shown in Figures 2, 3 and 5, the aperture 29 is integrated in the pump housing 15 and extends between the two screws 14, wherein the line 29 is partially disposed in a section formed on the two screws 14. Within 35.

16‧‧‧Control unit; control and drive unit

40‧‧‧vacuum chamber

41‧‧‧Products

42‧‧‧Locking chamber

43,44‧‧Sliding door

45‧‧‧ conveyor belt

46‧‧‧Supercharged pump

47‧‧‧Front pump

48‧‧‧Valves

49‧‧‧ Bypass valve

50‧‧‧ Controller

Claims (15)

A method for evacuating a cavity, wherein a pump is configured to be connected to the chamber by a booster pump and a downstream front pump, and the method has the following steps: a. speeding up the booster Pumping b. The gas from the chamber is introduced into the booster pump such that the booster pump temporarily draws excess power beyond the power provided by the booster pump; and c. transmits the Gas to the outlet of the booster pump, wherein i. as long as the outlet pressure of the booster pump is above a predetermined threshold, the gas is discharged through a bypass valve; ii. when the boost pressure of the booster pump has been When the temperature is below the threshold, the gas is forwarded to the pre-pump; d. The pre-load is used to compress the gas supplied by the booster pump. The method of claim 1, wherein the booster pump is accelerated in step a in the event that the inlet of the booster pump is closed. The method of claim 1 or 2, wherein at its peak, the excess power is equal to at least 50%, preferably at least 100%, and more preferably 200% of the driving power. The method of any one of claims 1 to 3, wherein the excess power is drawn at least 10%, preferably at least 20%, and more preferably at least 50% of the venting procedure. The method of any one of clauses 1 to 4, wherein the venting process begins The speed of the booster pump is above 8000 rpm, preferably above 10,000 rpm, and more preferably above 12,000 rpm. The method of any one of claims 1 to 5, wherein at its peak, the outlet pressure of the booster pump is at least 1 bar above atmospheric pressure, preferably at least 2 bar, and more preferably at least 3 bar. The method of any one of claims 1 to 6, wherein the chamber is a lock chamber and the lock chamber is operated with a cycle time of less than 15 seconds, preferably less than 10 seconds. The method of claim 7, wherein the excess power is at least 5%, more preferably at least 10%, of the cycle time at which the boosting chamber draws the lock chamber. A pump configuration having a booster pump and having a front pump, wherein the booster pump outlet is connected to the inlet of the front pump, wherein the booster pump and the front pump Between the two, a bypass valve is disposed, and the gas transmitted by the booster pump can be discharged by the bypass valve while bypassing the front pump, wherein a control unit is assembled if the booster is When the speed of the pump is higher than a predetermined speed threshold, a control signal is output, so that the booster pump is ready to extract excess power. The pump configuration of claim 9, wherein the speed threshold is higher than the pump's transmission speed, preferably at least 30% higher, and more preferably at least 50% higher. A pump configuration as claimed in claim 9 or 10, wherein the speed threshold is above 8000 rpm, preferably above 10,000 rpm, and more preferably above 12,000 rpm. A pump configuration according to any one of claims 9 to 11, wherein the booster pump A screw type pump. The pump configuration of claim 12, wherein the screw of the screw type pump has two threads in all cases. A pump arrangement according to any one of claims 9 to 13, wherein a housing for accommodating the screws is provided, and wherein the housing is designed such that, in the region of a thread, it has a first housing portion And a second housing portion, wherein the first housing portion has a suction gap between the housing and the thread, and wherein the second housing portion has a housing in the housing The radial minimum spacing between the body and the thread. The pump configuration of claim 14, wherein the housing has an inlet aperture and wherein the inlet aperture is 60%, preferably 80%, and more preferably 100% larger than the cross-sectional area of the thread.